1. Field of the Invention
The present invention relates to a tone plate for use in a keyboard-type tone plate percussion instrument, which is adapted to vibrate to thereby generate a musical tone of a specific tone pitch when struck, a method for fabricating the tone plate, a tone generator unit of a tone plate percussion instrument including tone plates and a resonance box for causing musical tones generated by the tone plates to resonate therein, and a keyboard-type percussion instrument.
2. Description of the Related Art
As disclosed in Japanese Utility Model Laid-open Publication (Kokai) No. H05-081895, a conventional keyboard-type tone plate percussion instrument includes, as sounding members, a plurality of tone plates each adapted to generate, when struck, a musical tone of a specific tone pitch (hereinafter referred to as the first prior art). The tone plates are generally formed into a flat plate, and in most keyboard-type tone plate percussion instruments, they are differed from one another mainly in length so as to generate different specific tone pitches.
In the tone plate percussion instrument of this type, it has also been known to provide a resonance box for causing musical tones generated by a plurality of tone plates to resonate therein. For example, the keyboard-type tone plate percussion instrument according to the first prior art is provided with a resonance box having resonance chambers in each of which a corresponding one of musical tones generated by the tone plates is caused to resonate.
In this keyboard-type tone plate percussion instrument, the tone plates constituting a tone plate group are fixed for vibration by means of a pin or the like to a supporting part, which is turn fixed to the musical instrument main body. The resonance box is arranged close to the tone plate group and fixed to the instrument main body by wood screws extending through elongated holes that are formed in resonance-box fixing rails attached to the instrument main body.
Further, as disclosed in the keyboard-type tone plate percussion instrument according to the first prior art, it has been known to provide percussion units such as hammer action units in the percussion instrument in addition to sounding members such as tone plates, whereby in response to a key depression operation, a corresponding percussion unit hits a corresponding one of the sounding members to thereby generate a musical tone of a specific tone pitch.
In this keyboard-type tone plate percussion instrument, the sounding members are fixed for vibration to a supporting part of the instrument by means of a pin or the like, and resonance boxes are provided that have an opening side arranged close to the sounding members. The percussion units are each disposed below a corresponding one of the sounding members. The just-mentioned mechanism is constructed into an upper and lower two-stage structure.
In the keyboard-type tone plate percussion instrument based on the first prior art, however, the tone plate group and the resonance box are fixed to the musical instrument main body independently of each other, making it difficult to carry out the mounting operation thereof to the musical instrument. In addition, the tone plates must be mounted one by one, thus further complicating the tone plate mounting operation.
In order to change the tone color of this tone plate percussion instrument, the tone plate group and/or the resonance box must be individually replaced by different ones. Upon such replacement, a fine adjustment is required of the distance and positional relation between the tone plate group and the resonance box in order to maintain the desired sounding capability of the tone plate percussion instrument, which further increases the difficulty of replacement. This also applies to the maintenance of the tone plate group and/or the resonance box.
Moreover, in the keyboard-type tone plate percussion instrument according to the first prior art, there is a fixed, one-on-one based relationship between the keys, percussion units, and sounding members. Therefore, when any one of the keys is depressed, a percussion unit fixedly corresponding thereto is driven to strike a sounding member, which in turn fixedly corresponds to the driven percussion unit. Thus, that sounding member which is struck by a given percussion unit is always the same. It is therefore impossible to carry out key transposition, for example. From the viewpoint of providing a variety of musical performances, there is a room for improving the keyboard-type tone plate percussion instrument.
Still another type of tone plate has also been known as disclosed in Japanese Patent Laid-open Publication (Kokai) No. H08-202351, in which the tone plate has its thickness varying in the longitudinal direction thereof. The tone plate is made thinner at a longitudinally center portion thereof by cutting or the like so as to attain a frequency ratio of 1:4:8 between primary, secondary, and tertiary modes in which the tone plate vibrates, thereby improving harmony, volume, and interval of chord tone generated by the tone plate percussion instrument (hereinafter referred to as the second prior art)
However, in the keyboard-type tone plate percussion instrument according to the second prior art, tone plates for generating lower pitch tones are made longer in entire length. In particular, tone plates for a low tone pitch range are wide in width and extremely long in entire length. The necessity for satisfying the above requirement for the tone plate size poses a problem that the degree of freedom in design decreases. For example, this results in increase in the entire instrument size, especially in a case where the keyboard-type tone plate percussion instrument includes a large number of tone plates so as to cover a wide range of pitch.